Critical Assessment of Electron Spin Resonance Studies on Cu(I)−NO Complexes in Cu−ZSM-5 Zeolites Prepared by Solid- and Liquid-State Ion Exchange

2005 ◽  
Vol 109 (42) ◽  
pp. 19723-19731 ◽  
Author(s):  
V. Umamaheswari ◽  
Martin Hartmann ◽  
Andreas Pöppl
Keyword(s):  
Electron Spin Resonance ◽  
Ion Exchange ◽  
Electron Spin ◽  
Liquid State ◽  
Critical Assessment ◽  
Spin Resonance

MNII-FULVIC ACID COMPLEXING EQUILIBRIUM MEASUREMENTS BY ELECTRON SPIN RESONANCE SPECTROMETRY

1977 ◽  
Vol 57 (1) ◽  
pp. 47-53 ◽  
Author(s):  
D. S. GAMBLE ◽  
M. SCHNITZER ◽  
D. S. SKINNER
Keyword(s):  
Electron Spin Resonance ◽  
Ion Exchange ◽  
Fulvic Acid ◽  
Electron Spin ◽  
Weighted Average ◽  
Outer Sphere ◽  
Water Soluble ◽  
Exchange Method ◽  
Spin Resonance ◽  
Esr Spectrometry

Electron spin resonance (ESR) spectrometry was used to determine weighted average equilibrium functions [Formula: see text] for water-soluble complexes formed between fulvic acid and divalent manganese. [Formula: see text] values ranged from 0.2 × 10−2 (at pH 6.15) to 0.5 × 10−3 (at pH 6.45) and were in excellent agreement with [Formula: see text] values determined previously for Mn–fulvic acid complexes by an ion-exchange method. The ESR method was found to be more sensitive, convenient and faster than the ion exchange procedure. From the data presented in this and in earlier publications it appears that MnII is bound simultaneously electrostatically and by hydrogen-bonding as Mn(OH2)62+ to fulvic acid donor groups in outer sphere complexing sites. These complexes are likely to be unsymmetrical.

Sign in / Sign up

Export Citation Format

Share Document